Seems like somebody really doesn't like the DC9s (or just NWA)! IIRC it was snowing when the DC9 went off the runway in MKE. I think I feel safer on a plane like that - that's undergone such significant mx checks over the years, and had time for flaws to be fixed - than a CR9 or E190 that's brand new...
Not that I think it's all that significant, but there have been cases of not finding out a problem or flaw until the aircraft type has been in the air for a few years, then it gets fixed (biggest example is obviously the DC10). I don't think I'd be willing to fly a CRJ that is 40 years old, but the DC9s, aside from guzzling gas, are good aircraft...I think that's been proven time and again. They may only be worth scrap, but a lot of that has to do with newer more efficient aircraft available on the market today, and that fleet type simply doesn't fit most airline's business models today (the 717 couldn't make a go of it either...).
Further, that's the advantage of having experienced pilots! Steve Forbe's Fact and Comment from a few weeks ago argued that the retirement age be increased for pilots, since experience is so important. They don't state his age, but I'd imagine the pilot had been flying DC9s for a while!